In last week's Security Weekly, I discussed how the lack of terrorist tradecraft skills has long plagued the jihadist movement. The al Qaeda core has had the most success projecting terrorist power transnationally, but even its operatives have often practiced sloppy terrorist tradecraft. Tradecraft mistakes by al Qaeda operatives have led to plots being detected or botched, including the millennium bomb plots and Operation Bojinka. Sloppy tradecraft also jeopardized successful attacks such as the 1993 World Trade Center Bombing and the 9/11 attacks.

This amateurish level of tradecraft was sufficient in an era such as the early 1990s, when few people were aware of the threat posed by the jihadist movement and few resources were dedicated to countering the threat. However, in the wake of 9/11 the environment became far more hostile to jihadist plotters, and as the focus of every intelligence and law enforcement agency became firmly fixed on the jihadist threat, terrorist operatives' ability to operate transnationally was severely diminished. That is the reason the threat of a spectacular follow-up attack to 9/11 never materialized.

Terrorist threats must be assessed considering two elements: intent and capability. Al Qaeda and other jihadist groups clearly have the intent to attack the U.S. homeland, something that is evident in their rhetoric and their repeated attempts to strike. But what these jihadist groups lack is the capability to fulfill their intent. They do not possess the terrorist tradecraft necessary to bypass the security measures instituted in the wake of the 9/11 attacks or the subsequent enhancements to those measures. Tradecraft is also not quickly or easily learned, and acquiring it through practical experience is difficult for a movement that often uses suicide operatives. These constraints have resulted in terrorist operatives with limited tradecraft capabilities.

Response to Limited Capability

The frustration that jihadists have experienced because of their inability to attack the United States through traditional forms of terrorism -- most notably by sending terrorist operatives to the United States to conduct attacks -- has prompted them to explore alternate approaches. One such strategy has been to attack U.S. aircraft from overseas, circumventing the need to operate inside the United States. This was really a re-emergence of an old tactic, which had previously been employed by Palestinian terrorist groups in various attacks including Pan Am 830, by the Libyans in Pan Am 103 and al Qaeda in the aborted Operation Bojinka (though these past plots did not involve the more recent al Qaeda innovation of suicide operatives.) Since 9/11, we have seen many other plots to attack U.S. aircraft with devices originating from abroad such as the shoe bomb plot, the liquid bomb plot, two underwear bomb plots and the printer bomb plot.

In addition to attempting to directly conduct terrorist attacks themselves, militant ideologues began using their influence to radicalize grassroots jihadists already living in the United States and the West, encouraging those radicalized individuals to conduct terrorist attacks where they live. Initially, this tactic seemed to be successful, producing the Little Rock and Ft. Hood shootings in the United States. Indeed, al Qaeda in the Arabian Peninsula founded their English-language Inspire Magazine in the wake of these two attacks to radicalize grassroots jihadists and to instruct them how to conduct simple attacks. A year later, the al Qaeda core group embraced this approach, releasing avideo by Adam Gadahn that encouraged grassroots jihadists to conduct simple attackswhere they live.

The Conundrum

Gadahn and al Qaeda in the Arabian Peninsula ideologue Anwar al-Awlaki urged grassroots jihadists to conduct "simple attacks" using knives, firearms or simple explosive devices. "Build a bomb in the kitchen of your mom" and use them against soft targets, they said. Simple attacks are within the reach of untrained grassroots jihadists. They are also very well suited to the skillsets of jihadists who have received basic military training in places like Syria and Iraq. In other words, they are people who know how to handle firearms and who understand the basics of tactical shooting but lack training in sophisticated terrorist tradecraft.

The poor terrorist tradecraft most jihadists possess and the type of training most receive in places such as Iraq, Syria and Yemen have meant that when jihadists have attempted to plan and conduct spectacular bombings, they have almost always been botched or uncovered by the authorities. An example of a botched attack is the May 2010 Times Square attack, in which Faisal Shahzad was able to obtain the materials required to build a car bomb but was unable to properly assemble a functional improvised explosive device. An example of a plot that was uncovered and thwarted by the authorities is theSeptember 2009 plot to bomb the New York subway system that involved Najibullah Zazi.

In 2010, considering the training and capability of most jihadist militant actors and the new emphasis on simple attacks, I concluded we were about to see a shift in jihadist terrorist tactics away from failed bombings and toward armed assaults. However, the attempt by jihadist ideologues to change the mentality of jihadist operatives has been largely unsuccessful, and it did not produce the volume of expected attacks. We have seen a few simple attacks conducted by such people, including shootings in Frankfurt, Germany, in March 2011; in Toulouse, France, in April 2012; and in Brussels, Belgium, in June 2014. The April 2013 Boston Marathon bombing is a case of unsophisticated jihadists using the bomb-making instructions in Inspire Magazine to conduct a simple attack.

Despite the intensive media coverage and hysteria caused by a simple attack like the Boston Marathon bombing, we have yet to see a large percentage of the grassroots jihadist militant world adopt the "simple attack" concept. For every successful simple attack we have seen, there have been multiple would-be militants such as Terry Lowen,Adel Daoud and Quazi Nafis who have aspired to attacks beyond their capabilities and failed.

This is partly because, apparently, most jihadists prefer to fight on the battlefield against foes like the Syrian military rather than attack civilian soft targets. But beyond the jihadist preference to travel to fight rather than to conduct attacks at home, there is another conundrum that puzzles me. Although most jihadists believe that it is permissible to give one's life during an attack, they continue to aspire to spectacular attacks that are beyond their capabilities and that have a very high chance of failure rather than to simple attacks that are certain to succeed. I am not a psychologist, but I speculate that perhaps there is something in the psychological makeup of people drawn to the ideology of jihadism that causes them to gravitate toward the spectacular rather than the obtainable. Perhaps they also believe that in order to justify their suicide, the attack must be spectacular.

I am not the only one puzzled by this tendency. It also appears to confound the al Qaeda ideologues who do not see the "harvest" of attacks they anticipated. Such people are used to seeing their directives carried out on the battlefield, and they surely must be perplexed that grassroots jihadists continue to botch attacks or walk into sting operations rather than conduct simple attacks within their capabilities.

But it does appear that al Qaeda in the Arabian Peninsula is attempting to adapt to the situation. In response to the ambition of grassroots jihadists, the group has attempted to equip them to conduct the types of spectacular attacks they aspire to. In the 12th edition of Inspire Magazine, published in March 2014, the Open Source Jihad section was titled "Car Bombs Inside America" and contained instructions for building a vehicle bomb. The group republished the section Aug. 16 along with some other previously published material (including the pressure cooker bomb plans used in the Boston Marathon bombing) in a publication entitled "Palestine Betrayal of the Guilty Conscience."

So far, we have not seen any attacks, attempted attacks or thwarted plots containing these vehicle bomb instructions. Still, the instructional material is out there, and given the number of past plots in which individuals attempted to follow the magazine's pipe bomb and pressure cooker bomb instructions, it may only be a matter of time before we see someone attempt to build and deploy a car bomb using these plans. In the meantime, the directions contained in "Car Bombs Inside America" have given intelligence and law enforcement officers new indicators of bomb making activity to look for.